dbmanager.java

JAVA编程思想源代码 值得一下 很难找的

package chapter10.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class DBManager {

	private static DBManager INSTANCE = null;

	public static final String DB_DRIVER_TYPE = "DBDriverType";

	String dBDriverType;

	public static final String DB_USER = "DBUserName";

	String dBUserName;

	public static final String DB_PASSWD = "DBPassword";

	String dBPassword;

	public static final String DB_Url = "DBUrl";

	String dBUrl;

	private Connection connection = null;

	private Statement statement = null;

	public DBManager() {
		// 初始化时，初始化各种参数，包括驱动名，用户名，密码和数据库URL
		dBDriverType = ResourceManager.getDBValue(DB_DRIVER_TYPE);
		dBUserName = ResourceManager.getDBValue(DB_USER);
		dBPassword = ResourceManager.getDBValue(DB_PASSWD);
		dBUrl = ResourceManager.getDBValue(DB_Url);

	}

	public void connectDB() throws ClassNotFoundException, SQLException {

		// mysql
		Class.forName(dBDriverType);
		connection = DriverManager.getConnection(dBUrl, dBUserName, dBPassword);
		statement = connection.createStatement();

	}

	public Connection getConnection() {
		return connection;
	}

	public void cleanUp() throws SQLException {
		try {
			statement.close();
			connection.close();
			statement = null;
		} catch (NullPointerException e) {
			e.printStackTrace();
		}

	}

	/**
	 * @return Returns the dBPassword.
	 */
	public String getDBPassword() {
		return dBPassword;
	}

	/**
	 * @return Returns the dBUserName.
	 */
	public String getDBUserName() {
		return dBUserName;
	}

	/**
	 * @return Returns the statement.
	 */
	public Statement getStatement() {
		if (statement == null) {
			try {
				connectDB();
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		return statement;
	}

	/**
	 * @return Returns the iNSTANCE.
	 */
	public static DBManager getINSTANCE() {
		if (INSTANCE == null) {
			INSTANCE = new DBManager();
		}
		return INSTANCE;
	}

	public void inquire() {
		// Statement statement;
		// try {
		// statement = connection.createStatement();
		// statement.execute()
		// statement.close();
		// } catch (SQLException e) {
		// // TODO Auto-generated catch block
		// e.printStackTrace();
		// }

	}

	public static void main(String[] args) {
	}

}